Mike Irizarry, CTO of US Cellular, revealed the nation’s fifth-largest operator is gearing up for a new mmWave 5G trial as it maps out plans to deploy next generation technology.

Unlike US Cellular’s previous 5G tests, Irizarry told Mobile World Live the upcoming trial at 28GHz will include standards-based 5G equipment, as well as tests of previously unavailable 5G core technology which will be essential for network slicing.

Irizarry declined to name US Cellular’s test partner, but Nokia appears to be the likely contender. The vendor has a pending application with the Federal Communications Commission (FCC) for 28GHz tests with a potential customer in Peoria, Illinois (about three hours from US Cellular’s Chicago headquarters) and a 1 September start date is consistent with a commencement time frame Irizarry mentioned.

The CTO said US Cellular views mmWave as hotspot spectrum, ideal for deployments in areas including campuses, event venues and manufacturing locations which demand extreme speed. Broad coverage and moderate speed can be supplied via 5G deployments on low- and mid-band spectrum, he added.

But Irizarry said US Cellular is also evaluating mmWave for backhaul.

“One of the challenges with deploying small cells is getting fibre to these small cells. If I can use mmWave to cell haul from an adjacent macro cell, I make my deployment of small cells, whether they’re for 4G or 5G, a lot easier.”

US Cellular does not own any mmWave assets: its current holdings include 600MHz, 700MHz and 800MHz low-band spectrum; along with mid-band airwaves in the PCS and AWS bands. But Irizarry said the operator is evaluating opportunities which may arise through the FCC’s upcoming mmWave auctions.

Timeline
Timing is tricky: Irizzary said US Cellular isn’t planning to sit on the sidelines as other operators launch 5G and attempt to poach customers, but noted it makes no sense to deploy a 5G network if there are no devices to take advantage of it. Compatible smartphones aren’t expected to become available until 2019.

“We will respond, one if our customers are asking for the technology, and two if we feel there’s a competitive threat in our markets.”

While deployment plans are still up in the air, he estimated the operator could launch 5G on its existing low- and mid-band spectrum holdings within a 14- to 18-month time frame.

Other work
5G planning is just one part of the effort US Cellular is putting into its network.

Irizarry said the operator is also testing self-optimising network technology with Ericsson, Nokia and Cisco. The goal, he said, is to use automation and machine learning to help alleviate increasing pressure placed on performance engineers as the network becomes more complex with the introduction of more small cells and C-RAN technology.

Additionally, the company is aiming to bolster its LTE network through densification and the introduction of 4G beamforming.

He added US Cellular is testing LTE-M technology and is in the process of plotting a deployment plan.